It took a bit of time to load the key-value pairs. We recommend reducing the number of key-value pairs in use.
Step 1: Audit the Key Values that are active by running a report in Ad Manager
Step 2: Remember NOT to delete any key-value pairs necessary for PubGuru header bidding to work. See:
Step 3: Export the report and see which ones are NOT necessary, then have them deactivated under Inventory > Key-values
Step 4: Check if you have key-value targeting in your source code and if they are necessary. Delete anything that’s not in use.